Conversion of pyrethroid isomers to more active species

Details Conversion of pyrethroid isomers to more active species Conversion of pyrethroid isomers to more active species

C - Chemistry, Metallurgy

07

C

260/496.6

C07C 253/30 (2006.01) C07C 255/39 (2006.01) C07C 255/53 (2006.01)

Patent

CA 1314559

ABSTRACT: Crystallizable pyrethroid isomers or enantiomer pairs are converted to more pesticidally active isomers by contacting a hydrocarbon slurry of the starting isomers with a base and a catalyst, the catalyst being substantially soluble in the slurry and selected from a quaternary ammonium compound, a quaternary phosphonium compound and a crown ether, agitating the slurry while maintaining a temperature effective for conversion, and recovering the resulting isomers. The tendency to form benzoin ester by-product is reduced by including in the slurry a weak base, an aldehyde scavenger such as a metabisulfite, and/or a tetraalkyl(C1-C5)ammonium halide catalyst dissolved in an aprotic solvent such as an organic nitrile. The process typically is effective for enriching cypermethrin, cyfluthrin and (cyano)(3-phen- oxyphenyl)methyl 3-(2,2-dibromoethenyl)-2,2-dimeth- ylcyclopropanecarboxylate in the more active species.

567489

Affiliated with

Also associated with

Rating

Conversion of pyrethroid isomers to more active species does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Conversion of pyrethroid isomers to more active species, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Conversion of pyrethroid isomers to more active species will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFCA-PAI-O-1333943